Entry No. 22 — the Durango file — filed under: soak
The Mother Spring
“The Utes named it Pagosah: healing water, or water that smells bad.”
The steaming aqua pool between The Springs Resort and the bank next door holds a Guinness record nobody can finish measuring. Surveyors dropped a 1,002-foot plumb line in 2011 and never touched bottom; Colorado School of Mines and USGS crews tried again in 2020 with the same result. The surface runs around 144 degrees, too hot to soak, but it feeds the resort's 50-plus pools and the free riverbank tubs. The Utes named it Pagosah: healing water, or water that smells bad.
The story
On paper, it looks like a standard landscaped water feature tucked between the resort grounds and a bank parking lot off Hot Springs Boulevard. But the opaque turquoise water steaming inside the stone rim isn't decorative—it's the Mother Spring, and nobody actually knows where the bottom is. In 2011, hydrologist John Casey dropped a 1,002-foot plumb line into the pool to officially claim the Guinness World Record for the world's deepest geothermal hot spring. The cord ran completely out before touching solid ground. Nine years later, crews from the USGS and Colorado School of Mines dropped their own instruments down the abyss and got the exact same result: nothing but water all the way down.
Long before surveyors brought measuring tape, the Utes called the thermal anomaly *Pagosah*—a name translated alternately as "healing water" or "water that smells bad" (both are entirely accurate). At the surface, the pool sits at a lethal 144 degrees Fahrenheit, meaning you wouldn't recover from a dip in the main vent so much as cook in it. Instead, this unmeasured underground cauldron acts as the geothermal engine for the entire area, plumbing thermal water out to feed more than 50 terraced soaking pools at the resort next door and spilling directly into free rock tubs along the riverbank.
What it's like
You don't need a resort wristband or a ticket to look into the world's deepest spring; it sits out in the open just off the San Juan Riverwalk near the resort edge. You'll smell the sharp, egg-sulfur vapor before you reach the edge, where the eerie, opaque aqua water simmers with barely a ripple. Fences and near-scalding temperatures keep everyone at arm's length, so take five minutes to stare into the endless blue hole, then head down the paved path to sample the cooled-down runoff on the river's edge.
The move: Peer over the edge into the bottomless aqua water, then go soak in what it feeds: book a terraced pool at the resort or claim a free rock tub across the San Juan.
📍 Before you go The spring sits in plain view on The Springs Resort grounds off Hot Springs Boulevard, between the resort and the bank next door, and you can walk up for a look without buying a soak pass. It is a short, flat stroll from the resort parking area or from the San Juan Riverwalk on the other side of the river. Soaking in the Mother Spring itself is prohibited since the surface hovers near 144 degrees; to get in the water, use the resort pools it feeds or the free rock-lined tubs on the town side of the river. Pair it with Nathan's Hippy Dip and a Riverwalk loop through downtown.
- 📍 Pagosa Springs
- 💸 $$
- ⚡ Up for anything
- 🌗 Indoors
Where: 323 Hot Springs Blvd, Pagosa Springs, CO 81147 (on The Springs Resort grounds, beside the San Juan Riverwalk)
Hours: Added 2026-06-11 — confirm current hours before you go.
Pair it with
- Nathan's Hippy Dip Hot Spring — Walk a few hundred yards down the riverwalk from the Mother Spring to soak in its geothermal water for free right where it spills into the San Juan River.
- Piedra River Hot Springs — If you want geothermal water without resort fences and concrete terraces, drive 18 miles west to find hand-dug rock pools along the Piedra River.
- Chimney Rock Night Sky & Lunar Standstill Programs — Pair an afternoon staring into a bottomless geothermal spring with an evening 17 miles away watching the dark skies over ancient Ancestral Puebloan ruins.
Good to know
Do I need to pay or buy a pass to view the Mother Spring?
No. The Mother Spring sits on visible resort grounds near the riverwalk, and anyone can walk up for a look free of charge without purchasing a resort pass.
Can you soak directly in the Mother Spring?
No. The spring surface stays near 144 degrees Fahrenheit, making direct soaking dangerous and strictly prohibited. You soak in the temperature-controlled pools or free riverbank tubs fed by it.
How deep is the spring?
Nobody knows. Plumb lines dropped to 1,002 feet in 2011 hit no bottom, and follow-up attempts in 2020 by the USGS and Colorado School of Mines failed to find the floor as well.
Why does the spring water smell like sulfur?
The water carries high mineral loads from deep underground, giving off a distinct sulfur scent. The Ute name Pagosah loosely translates to either 'healing water' or 'water that smells bad.'
Plan a visit & invite your people →
Further reading: Atlas Obscura · Wikipedia · Official site · guinnessworldrecords.com
last checked: 2026-06-11